Adhesive applicator

ABSTRACT

Cam-activated pressure wheels press desired portions only of the blank against continuously revolving adhesive-applicator wheels as the conveyor moves the blanks thereover. Means driving the applicator additionally rotates a vertically disposed disc which is partially immersed in an adhesive supply and whose upper portions lie closely adjacent to the applicator container whereby the adhesive is carried from said supply and scraped off the disc to be deposited in the container.

United States Patent 1191 Kalikow 1111 I 3,797,454 1 Mar. 19, 1974ADHESIVE APPLICATOR [76] Inventor: Peter Kalikow, 870 United NationsPlaza, New York, NY. 10017 221 Fiietr. Dec. 20, 1972 21 Appl.No.:316,830

Related Application Data 1 [62] owr rraersar. Nof'l 78,763. Sept. 8,1W1, Pat. No.

[52] US. Cl. 118/247, 118/429 [51] Int. Cl. B05c 1/02 [58] Field ofSearch 1. 118/211, 212, 227, 247,

[56] 1 References Cited UNITED STATES PATENTS 437,435 9/1890 Howe117/111 R 2,633,063 3/1953 Ohrn.. .1 11s/247'x 3,001,505 9/1961 Novick 1118/258 x 3,240,185 3/1966 Goepner 118/247 Primary Examiner -MorrisKaplan [57] ABSTRACT 3 Claims, 6 Drawing Figures I. l I23 1 13s a s 126Q 116 24 I32 s. 133 l3l 130 Q PATENTED MAR l 9 I974 SHEU 1 BF 3 FIG.|

FIG.2

shat-454 PATENTEDIAR I 9 m4 SHEET 3 [IF 3 ADHESIVE APPLICATOR BACKGROUNDOF THE INVENTION This invention relates generally to box formingmachines and, more particularly, it relates to machines forming boxesfrom pre-scored blanks. Such machines comprise means for moving a blankfrom a storage section to an adhesive applicator, means for moving theblank from the applicator to the box-forming station, the latter takingmany forms but often comprising a die and ram assembly. Typical of themany patents in this field is U.S. Pat. No. 3,102,457 of Walker. Allsuch machines are complex electromechanical devices which are expensiveto build, and require substantial maintenance. Particular trouble isexperienced with adhesive applicators, as they tend to clog with driedadhesive if not rigorously maintained, and tend to deliver either toolittle or too much adhesive. The latter is the more serious problem; toolittle adhesive may result in a box that is unsatisfactory but which isreadily removeable, but too much adhesive will result in adhesivesmearing onto portions of the machine where it can disrupt the entireoperation and necessitate a shutdown for clean ing.

. Adhesives used heretofore are solvent-based systems employingchemicals which oxidize or polymerize on contact with air as the solventevaporates. Heat may or may not be employed to drive off the solvent andaccelerate the reaction. The adhesive bond is not established until theadhesive is dry and in some cases cured. Once the solventis drivenoff,'the oxidation or polymerization reactions proceed irreversibly,which means that adhesives must'be stored in tightly closed containers,as once they are exposed to the atomosphere the solvent starts toevaporate, the viscosity starts torise (changing its wettingproperties). and, if not used promptly, it deteriorates. More recently,so-called contact cements have come into use. These are alsosolvent-based systems, but have the advantage of forming an adhesivebond immediately upon contact of the coated surfaces. However, contactcement solvents must be driven off before the surfaces are pressedtogether which mitigates against its use in automatic high speedequipment. Also, the solvents are extremely flammable, and great cautionmust be exercised in their use. In emulsion-based adhesive systems, asubstantial compression time is required before a bond isformed,necessitating very largemachines. Also, emulsions settle in time,limiting shelf life.

The development of .hot melt adhesives represents a significant advancein the adhesiveart. Such adhesives form bonds by different reactions andcontain no solvents which must be driven off. In contrast to emulsionsystems, they are supplied in a dry, particulate or granular form whichis storage stable and does not require protection from the atmosphere.The adhesive properties are not developed until the material is meltedand heatedto a temperature. above about,300F. Even in the molten stateit is not affected by exposure to the attages for use in automaticequipment, and the present invention is specifically designed therefore.A line of hot melt adhesives is marketed as Cascomelt (trademark)pellets, by Borden Chemical Co. Different for- 5 mulations are providedfor packaging which will be subjected to freezing temperatures, highheat or humidity, etc.

OBJECTS OF THE INVENTION An object of the invention is to provide anovel adhesive applicator assembly for use in box forming machines whichreliably dispenses a precisely controlled quantity of adhesive ontoselected areas of pre-scored blanks.

A still further object of the invention is to provide a novel ram anddie assembly for use in box forming machines.

Various other objects and advantages of the invention will become clearfrom the following detailed de- 20 scription of an embodiment thereof,and the novel features will be particularly pointed out in connectionwith the appended claims.

THE DRAWINGS Reference will hereinafter be made to the accompa- 30 ment;

mosphere, since there are no solvents involved, so conditions of, useare not critical. It bonds on contact by rapid heat dissipation, andrequires no preliminary drying. Such adhesives manifestly present manyadvan- FIG. 3 is an end elevation of the adhesive applicator of theinvention; i

FIG. 4 is a cross-sectional elevation of the adhesive applicator;

FIG. 5 is a perspective view of the adhesive applicators and themounting assembly therefor;

FIG. 6 is a plan view of the adhesive applicator sec tion; 7 IDESCRIPTION OF EMBODIMENTS With reference to FIG. 1, km overallperspective view, the box forming machine 10 of the invention iscompactly constructed with steel side members 12, 14 held in spaced,parallel relation by a plurality of cross members. Machine 10 is mountedon casters 16 for increased mobility.

Broadly speaking, the machine 10 comprises a blank feeding or supplystation 18, a continuous adhesive applicator station 20, and a boxforming station 22.

The front of the machine can be considered to be side wall 14, since ithas control panel 24 mounted thereon, but in the following descriptionside wall 12 I will be considered the front side wall, wall 14 the rearwall, the blank feed section 18 as the right end and the box forming anddelivery section 22 as the left end, all of which is clear in FIG. 2.Further, it is to be noted that the machine is provided with suitablesafety guards and covers which are either not shown or are shown only inphantom.

The blank storing and feeding section 18 will now be described, andreference is made to FIG. 2. Side mem bers 12, 14 each extend-upwardlyat section 18 to support a pair of horizontal transverse rods 26, 28which are vertically aligned. The blank holder 30 is supported on rods26, 28 and may be moved therealong to accomodate blanks of differentwidths. More particularly, blank holder 30 comprises two identical butoppositely oriented assemblies. A block 32 is drilled for slidingengagement with rods 26, 28 (with set screws or other means provided tolock it in a desired position), and supports a first vertical blankguide 34 in the form of a right angle. Along, at least, one of its loweredges blank holder 34 has an 4 inwardly extending, downwardly slopingshoulder 36 which provides enough support, in combination with similarshoulders on the other three blank holders, to retain a stack of blanksbut not inhibit the feeding function, described below. Block 32 is alsodrilled, at right angles to the holes for rods 26, 28 to slidably engagea pair of horizontal longitudinal rods 38, 40, which in turn support asecond blank holder 42, similar to holder 34. By sliding rods 38, 40 inblock 32, different lengths of blanks can be accomodated. A second block44 also mounted on rods 26, 28 and two more blank holders 46, 48complete a mechanism adapted to hold a variety of blank sizes,supporting any blank in a vertical stack at each corner. A transversetie rod 50 connecting the two blank holder assemblies at the end removedfrom blocks 32, 44 adds rigidity to the structure.

A pair of upwardly facing suction cups 52 are located below theapproximate center of blank holder 30, and are adapted for verticalmovement between the bottom of blank holder 30 and the blank receivingtable 54.

The success of any box-making operation depends in large measure on theability of the machine to apply a precise amount of adhesive preciselywhere it is wanted. The adhesive applicator assembly of the inventionaccomplishes this, and will now be described. Attention is directed toFIGS. 36. In essence, two continuously rotating grooved wheels 112 aremounted just below the level of table 54 at transverse positionsselected so that tabs on the blanks or whatever portion adhesive is tobe applied to, passes directly thereover. The peripheral speed anddirection of rotation of wheels 112 is the same as the blank, and thewidth of the grooves determines the quantity of adhesive applied. As atab passes over wheels 112, a pair of cam activated pressure wheels 114move downwardly and press the tab against grooved wheel 112 for apredetermined period, thus depositing a plurality of stripes of adhesiveonto the tab.

In particular, and with reference to FIG. 4, each adhesive applicatorcomprises a cylindrical tank 1 l6 having its axis in the horizontalplane, and provided with a horizontal drive shaft 118 extending from oneend to the other just beneath the uppermost periphery. Grooved wheel 112is joumaled onto shaft 118 and retates therewith. Being of relativelysmall diameter, wheel 112 approaches line contact with the blank,resulting in a cleaner and more accurate adhesive pattern. The interiorof tank 116 forms an adhesive well 120, and a port 122 is provided forfilling. A vertical screen 123 prevents any foreign matter introducedthrough port 122 from damaging the applicator assembly. One or morethermostatically controlled electric cartridge heaters 124 are mountedin an end wall of tank 116 to establish and maintain the adhesive at itsproper temperature. Means are required to supply melted adhesive towheel 112 in unvarying fashion eventhough the amount of adhesive in well120 may vary from full to nearly empty. Accordingly, a small, opencontainer 126, is mounted around and just below wheel 112 and is adaptedto contain a very limited amount of adhesive in actual contact with thewheel surface and about Vs in. of the sides. Container 126 is suppliedwith adhesive by a simple pump. In particular, a gear 128 is joumaledonto shaft 118 adjacent wheel 112, and drives a pump gear 130 mountedfor rotation within well 120 on a shaft 132 located approximately on theaxis of container 116. Shaft 132 is mounted on a horizontal support 133.A smooth disc 131 is also mounted on shaft 132 and is integral with gear130. The diameter of disc 131 is such that it extends from nearly thebottom of well 120 to above the side of closely adjacent container 126.As the disc 131 rotates, it picks up the viscous adhesive from well 120and carries it above container 126. A vertical vane 135 on container 126scrapes adhesive off disc 131 and it flows into the container. Thismaintains it full, and any excess merely overflows the sides ofcontainer 126 and return to well 120. In this manner, grooved wheel 112is exposed to an unvarying quantity of adhesive at all times.

Mounting of the adhesive applicators and means for driving each shaft118 are shown in FIGS. 5 and 6. A rectangular frame comprising twoparallel rails 134, 136 with end members 138, 140 are transverselyattached to side walls 12, 14. Each adhesive applicator 116 is mountedon a pair of outwardly directed angles 142 adapted to ride on the rails134, 136. Locking means (not shown) are provided to secure applicators116 in a particular position. A worm gear 144 is journaled into endmembers 138, 140 and is parallel with rails 134, 136 and in the sameplane therewith. Gear 144 also engages applicators 116, but isleft-handed on one end and right-handed on the other, so that when crank146 at one end of gear 144 is turned, applicators 116 are moved alongrails 134, 136 either toward or away from each other, always maintaininga symmetrical relationship with the longitudinal axis of the machine.

As shown most clearly in FIGS. 3 and 6, the shafts 1 18 carry a sprocket148, which can be engaged or disengaged from shaft 118 by means of aclutch 150 (this allows the machine to be set up and its mechanicaloperation checked while heaters 124 are bringing the adhesive totemperature, without rotating grooved wheels 112). An endless chain 152connects sprocket 148 and a sprocket 154 joumaled onto the end of shaft108. The shaft 108, which also carries blank conveyor drive sprocket 106and conveyor chain 102, is journaled into side walls 12, 14.

The assembly and functioning of pressure wheels 114 is as follows. Thecam shaft 78 which carries eccentric cam 76 is joumaled through sidewall12 and carries lift cam 156 on its forward end. A cam follower 158 ismounted for partial rotation about a pivot shaft 160 and is biased intocontact with lift cam 156 by a spring 162. The free end of cam follower158 is connected to a tie rod 164, and connects cam follower 158 withpressure wheel shaft arm 166. The arm 166 is rigidly attached to one endof the pressure wheel shaft 168. Thus, when lift cam 156 raises camfollower 158, this motion is translated into slight counterclockwiserotation of pressure wheel shaft 168 by tie rod 164 and shaft arm 166.Pressure wheel shaft 168 traverses the machine and is joumaled into sidemembers 12, 14. Pressure wheels 114 are held above grooved wheels 112 ofthe adhesive applicators by brackets 170 secured to shaft 168 forrotation therewith. Thus, the speed of rotation and shape of cam 156determines when and for how long pressure wheels 114 will force a blankagainst grooved adhesive wheels 112.

It is to be noted that the table 54 is cut away from the area of groovedwheels 112 so that, after adhesive is ap plied to a blank, it issupported only in the area 54a around conveyor channel 98 and at itsedges by guides 96. This prevents adhesive on a blank from touching anypart of the machine. Further, the blank is maintained fiat as it passesover area 54a of table 54 and into box-forming section 22 by a pair ofweighted arms 172 which are loosely journaled onto shaft 168 by means ofcollars 174.

What is claimed is:

1. An adhesive applicator assembly adapted to apply adhesives incontrolled quantities to workpieces passing thereover comprising:

a well assembly for storage of said adhesive;

a grooved adhesive applicator wheel extending upwardly through anopening in the top of said well and mounted for rotation on a shaftadjacent the top of said well;

an adhesive container of limited capacity immediately below andpartially surrounding the lower portion of said applicator wheel;

a first gear mounted for rotation on said shaft:

a second gear driven by said first gear and mounted for rotation on asecond shaft located on the ap proximate central axis of said well;

a disc axially mounted on said second shaft for rotation with saidsecond gear and extending to near the bottom of said well and over thetop of said container, one side of said disc being closely adjacent to aside of said container, whereby adhesive adhering to said disc may bedeposited in said container when said disc is rotated; means forconstantly supplying adhesive from said well to said container as saidapplicator wheel is driven by said shaft; means to feed a said workpiecein a path superposed to, and closely spaced from, said applicator wheel;

pressure wheel means positioned over said applicator wheel andselectively moveable into engagement with said workpiece passingthereunder, said workpiece thereby being pressed into engagement withsaid applicator wheel;

cam means operatively associated with said wheel means whereby to effectsaid selective movement of said pressure wheels into engagement withsaid applicator wheel over preselected portions only of said workpiece;and

filter means disposed in said well and functionally operative withrespect to the disc feed to said container.

2. The adhesive applicator as claimed in claim 1, wherein said wellassembly comprises a horizontal cylindrical container having a closeablefilling port in the upper portion near the end removed from saidapplicator wheel, and said filter comprises a vertical screen meansintermediate said port and said disc.

3. The adhesive applicator as claimed in claim 1, and additionallycomprising thermostatically controlled heating means within said wellfor establishing and maintaining adhesive therein at an elevatedtemperature.

1. An adhesive applicator assembly adapted to apply adhesives incontrolled quantities to workpieces passing thereover comprising: a wellassembly for storage of said adhesive; a grooved adhesive applicatorwheel extending upwardly through an opening in the top of said well andmounted for rotation on a shaft adjacent the top of said well; anadhesive container of limited capacity immediately below and partiallysurrounding the lower portion of said applicator wheel; a first gearmounted for rotation on said shaft: a second gear driven by said firstgear and mounted for rotation on a second shaft located on theapproximate central axis of said well; a disc axially mounted on saidsecond shaft for rotation with said second gear and extending to nearthe bottom of said well and over the top of said container, one side ofsaid disc being closely adjacent to a side of said container, wherebyadhesive adhering to said disc may be deposited in said container whensaid disc is rotated; means for constantly supplying adhesive from saidwelL to said container as said applicator wheel is driven by said shaft;means to feed a said workpiece in a path superposed to, and closelyspaced from, said applicator wheel; pressure wheel means positioned oversaid applicator wheel and selectively moveable into engagement with saidworkpiece passing thereunder, said workpiece thereby being pressed intoengagement with said applicator wheel; cam means operatively associatedwith said wheel means whereby to effect said selective movement of saidpressure wheels into engagement with said applicator wheel overpreselected portions only of said workpiece; and filter means disposedin said well and functionally operative with respect to the disc feed tosaid container.
 2. The adhesive applicator as claimed in claim 1,wherein said well assembly comprises a horizontal cylindrical containerhaving a closeable filling port in the upper portion near the endremoved from said applicator wheel, and said filter comprises a verticalscreen means intermediate said port and said disc.
 3. The adhesiveapplicator as claimed in claim 1, and additionally comprisingthermostatically controlled heating means within said well forestablishing and maintaining adhesive therein at an elevatedtemperature.